Pasadena, Calif. — Somehow, in spite of the explosive, 24/7 competition of everything from streaming videos on the Internet to hit shows on basic cable and a $30 billion video-game industry, broadcast television networks manage to hold onto one of the last vestiges of an earlier era of media dominance, namely the ritual unveiling of the prime-time, fall TV schedule.

The season's 27 new shows on all five free networks will launch throughout the next few months, with most bowing in during the next few weeks. This is the first full-development lineup to roll out after the crippling 2007-08 writers' strike, and in many ways, say writers, producers, network executives, and industry analysts, this year's crop says as much about why, against many odds, network television remains an important cultural force as it does about the powerful changes profoundly and perhaps permanently altering its future.

"The broadcast networks, with their mandate to reach the biggest possible audience, and with the kind of resources they can still throw behind a project," says Elayne Rapping, professor of American studies at the University at Buffalo (SUNY), "are still the best potential source for our shared stories or collective myths, the ideas that tell us who we are."

"The networks are in a scramble to reinforce their traditional identities," says K.P. Anderson, executive producer of "The Soup." Remakes (The CW's "Melrose Place") and spinoffs ("NCIS: L.A"; Fox's "Family Guy" offspring, "The Cleveland Show") further reinforce the conservative approach to programming evident across the list, he adds.

But as other networks burnish their traditional assets, one network, NBC, has launched what some have called the most radical redefinition of prime time since the dawn of the TV prime-time schedule a half century ago. The entire industry has been tightening its belt over the past year, but none so much as NBC-Universal, which cut some $500 million. Its most visible and dramatic cost-cutting strategy, however, has been to pull all scripted dramas from the 10 p.m. prime-time slot and replace them, five nights a week, with a new comedy hour hosted by Jay Leno. "It was time to try something else," says the former "Tonight Show" host. "NBC tried scripted programming at 10 o'clock – "Lipstick Jungle," "Kidnapped," "My Own Worst Enemy." Hugely expensive shows. I thought they were OK, but for some reason, they didn't catch on. So now you try something different."

The move has led to much hand-wringing in the creative community and beyond. The 10 p.m. slot, notes writer Peter Tolan, was traditionally the home of many of television's finest dramas. "There was a level, a quality of work, and an elegance of work that NBC was known for. And I don't think, unless I'm wrong, that this will approach it."

He is quick to point out that as yet, the nightly comedy hour, which starts Sept. 14, is an unknown quantity. Nonetheless, he adds, the mere replacement of five hours of drama with a variety show format diminishes the television landscape. While he understands that unscripted programming is here to stay, "five nights a week is craven," he says.

The lasting impact will be how the industry itself retools in response.

Fellow writer Shawn Ryan says the move is short-sighted even from a financial standpoint, since scripted dramas can be packaged and resold whereas topical talk shows have little value after one airing. Beyond that, as fewer shows are scripted, the industry loses venues for developing the next generations of writers, producers, and performers.

The last time writers lost so much prime-time real estate to unscripted programming, "we never got it back," says executive producer Don Reo, who remembers the bitter 1988 writers' strike that ushered in the current era of so-called "reality" television. "There is a place for art in our entertainment landscape," says Mr. Reo, stories that mean something to a broad range of people.

Cable has certainly become an important crucible for new scripted shows. Many of the Emmy nominations for next week's awards show, including AMC's "Mad Men" and FX's "Damages," are from cable. But, says executive producer Mr. Anderson, cable audiences are a fraction of what the broadcast networks pull together. "Cable appeals to niche audiences. The broadcast networks are the last bastion of eventized entertainment that we can all share."

Newcomer Dan Harmon, executive producer on NBC's new comedy "Community," says that after working in the cable environment, he wanted to work on a large network, specifically because he valued the "big tent" idea. "I wanted to make a show for everyone, something that actually [harked] back to the days when TV shows had a handsome man for the ladies, a beautiful girl for the guys, and a car for the kids. That shared experience is getting harder and harder to find."

As Leno himself is quick to point out, the network is not a bunch of real estate in Los Angeles. The heart and soul of the broadcast network is the hundreds of affiliated stations in cities of all sizes across the nation.

The 10 p.m. shows serve as a lead-in to the affiliates' late-night news shows, he notes, the No. 1 profit center at most local stations. Any move that drains viewers before they are "delivered" to the 11 p.m. news hours could reverberate through the entire system.

"This could be the beginning of the unraveling of the affiliate network," he says, adding that if that happened, it would be an important evolutionary restructuring of the entertainment landscape.